Área Académica: Licenciatura En Sistemas Computacionales

Tema: Introduction To Database

Profesor: M.T.I. Juvencio Mendoza Castelán

Periodo: July / December/2011

Keywords. Database / Concept

• Tema: Introduction To Database

Abstract

One of the most important elements of an information system is the database, since

it is the essential part which will safeguard all transactions that a company makes.

For this reason it is important to know the types of databases that currently exist,

and some other elements such as a database manager (smbd), and its main

functions it performs. And what are the main operations you can perform with a

database.

Keywords: Database / Concept

What is a Database

• A collection of interrelated data stored together without

harmful or unnecessary redundancy. Shakuntala Atre (Technical Base

Structure Database Design and Admin.)

• A collection of interrelated files created by a DBMS. James Martin

(Organization of Databases)

• It is an organized list of data that provides a way to find

information quickly and easily from a reference point chosen Alice Y. Tsai H

A DBMS.

• Before I tell you the names of some database drivers, we must first understand

what that is. A DBMS (Data Base Manager System) is software whose purpose is

to provide a link between the user and a database to facilitate the manipulation of

information using primarily a programming language called SQL (Simple Query

Language) in words simple.

• The program handles most popular databases are: MySQL, PostgreSQL and

SQL-Server Oracle. There are many more but I mention these because they are

more stable, especially Oracle, but this is not free, you need to pay a license,

which does not happen with MySQL and PostgreSQL.

Tipos de Base de Datos

Fichero plano

Fichero plano

Fichero plano Fichero

plano

MANAGEMENT SYSTEM DATABASE

( D B M S )

Key Features:

Create and organize the database

Establish and manage the access paths BD

Manage the data according to user requests

Manage the integrity and data security

Record the use of data bases.

Database system (application)

It is the result of coding created in a DBMS and a database created in the same DBMS). This application will manage and organize a series of data. For example, we use SQL-Server (which is a DBMS) to bring the management (administration) of cards of items from our store by entering, modifying, updating, removing printer reports, etc.. We can for example make queries such as what item has been sold more this month? What customers buy a particular item? What is the gain of the month? and so on.

Objectives of Data Base Systems

The database systems are designed to handle large amounts of

information. For this system is useful when you retrieve the information

stored and there are no errors in either the storage or recovery, you

must meet certain requirements at the time of its design, among which

are:

Avoid redundancy, preserve the integrity, preserve the independence of

the data, maintain security, concurrent access

• PROBLEMS OF A FILE SYSTEM

Redundancy and inconsistency of data

Difficulty in accessing data

Isolation of the data

Concurrent access anomalies

Integrity problems

Security Issues

• Systems Languages Database Drivers

In common programming languages, declarations and

executable statements are all parts of speech, however, in

the world of databases, it is normal to separate the functions

into two separate languages (DDL and DML).

The reason is this: In an ordinary programming language,

variables and data are available only during the execution of

the program, change in a system database, the data must

exist forever, and must be defined for all processes.

The conceptual level is specified in a language that is part of

the DBMS, called Leguaje Data Definition (DDL Data Definition

Language)

which allows to describe the different types of entities (tables,

views, etc..), relationships and constraints between them and

therefore the DDL is used in the design of the database and

also when the design is modified but never used to get or

modify data.

The DDL is the part that varies from one DBMS to another, and

that has to do with how data are organized internally and

therefore, each system does in one way or another.

Among the most common instructions used by the DBMS are:

Create Table, Not Null, Primary Key, Unique, among others.

The DDL usually have two subsets of instructions

Data Definition Language

(DDL)

Data Manipulation Language

(DML)

DATA HANDLING BY WANT TO SAY:

recovery

insertion

elimination

modification

Bibliography

James L. Jhonson. Editorial. Data Base. Models, languages, design, Oxford. México,

2000

Adoration of Miguel Castaño, design databases. Problems solved. Editorial:

Alfaomega Ra-Ma. Colombia, 2001

TSAI YH: A database systems, management and use. ED.

Prentice Hall 1a. México Edition 1990.

Weiderhold, G database design. ED. MC. GRAW HILL 2nd.

Edition. México 1998.